1. Field of the Invention
The present invention relates to a chiropractic adjustor. More particularly, the present invention relates to a method and apparatus for assessing and correcting the relative compliance of vertebral segments for use with chiropractic adjustors.
2. Description of the Related Art
Controlled tests of spinal manipulative therapy have not been perceived as satisfying the requirements of investigators. However, spinal manipulative therapy is steadily gaining acceptance as a treatment modality for lower back pain.
Spinal manipulative therapy is any procedure which is used to mobilize, adjust, manipulate, apply traction, massage, stimulate, or otherwise influence the spine and paraspinal tissues with the aim of influencing the patient's health. The major theories on which manipulation is based include the reduction of disc prolapse, the correction of posterior joint dysfunction, the mobilization of fixated or blocked vertebral joints, the reduction of nerve root compression, the normalization of reflex activity, and the relaxation of muscles.
Consideration of the possible effects of manipulation on the structure of the spine has led to the postulation that there exists barriers to motion within the spinal joints which can be influenced by manipulation. A model representing the ranges of motion for each spinal joint is presented in FIGS. 1A to 1D. The "active" range of motion is that motion affected by muscles alone. Here, N designates the neutral position for the spinal joint and MA refers to the limit of muscle activity.
The active range is the range of motion in which normal exercise is performed and which is limited by the leverage capacity of muscles surrounding the joint. Beyond the active range of motion is the "passive" range of motion where external forces are used to effect stretching beyond the "active" range of motion. The limit of the "passive" range of motion, PB, is the so-called "physiologic barrier". Beyond that range is a smaller range of motion through which a joint can be moved without disrupting its ligaments. This range of motion can be entered by a quick thrust in the direction of joint movement. The limit of this range is the "anatomic barrier", AB, beyond which will result in the tearing of ligaments or bony collapse.
Normal motion, as shown in FIG. 1A, may be restricted in any of three ways which include muscle spasm, joint locking and bony restriction. In FIG. 1B, the muscles surrounding the joint are in spasm and the normal range of motion is restricted. In FIG. 1C, the joint has locked on one side, pulling the physiologic barrier towards the neutral position. Mechanisms for this restriction in motion include articular synovial pinching and disc herniation. In FIG. 1D, the bony structure has blocked movement through spur formation or deformity.
In the first two instances, manipulation may restore motion to the joint through releasing the muscle spasm and/or stretching the shortened muscles. In the instance where the motion is restricted due to joint locking, the motion may be restored by a manipulative thrust into the paraphysiologic space to stretch the ligaments and open facets. Bony obstructions to movement may not be susceptible to manipulation.
Identification of fixated vertebral segments has traditionally been accomplished through manual palpation of the spine and more recently through the observation of spinal motion with X-ray image intensifiers. However, this process requires skill to perform and often is slow and not very accurate.